This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Conventional two-photon fluorescent microscopy technique allows tissue imaging only at depths less than 1mm. The project goal is to develope a practical devise that will be capable of fluorescent imaging in tissue at depths of few mm and deeper. The novel proposed detection system utilized in the project possesses superior light collection efficiency and sensitivity that will allow imaging in deep layers of turbid media.